Mount Semeru Erupted on Wednesday Afternoon, Activity Level at Alert Level

Mount Semeru in East Java erupted again on Wednesday (February 18, 2026) at 15:31 WIB. In the last week, Mount Semeru has erupted 30 times.

Based on eruption information from the Center for Volcanology and Geological Hazard Mitigation (PVMBG) via the MAGMA Indonesia application, the observed ash column height reached None meters above the peak (None meters above sea level).

No eruption visuals were observed. The eruption was recorded on the seismograph with a maximum amplitude of 22 millimeters and a duration of 115 seconds.

(Read: Indonesia Has the Most Active Volcanoes in the World)

According to the MAGMA Indonesia volcano activity report, Mount Semeru's activity level is at Level III (Alert). Earthquake observations on February 18, 2026, from 06:00 to 12:00 WIB showed 20 eruption/explosion earthquakes with amplitudes of 10-22 millimeters and durations of 46-145 seconds.

Then, 1 emission earthquake with an amplitude of 8 millimeters and a duration of 47 seconds, and 1 harmonic earthquake with an amplitude of 2 millimeters and a duration of 266 seconds.

PVMBG advises against any activities in the southeast sector along the Besuk Kobokan, within 13 kilometers of the peak (eruption center). Beyond that distance, residents should not carry out activities within 500 meters of the riverbank along the Besuk Kobokan due to the potential for being affected by expanding hot clouds and lahar flows up to 17 kilometers from the peak.

In 2026, MAGMA Indonesia has recorded 663 volcanic eruptions across Indonesia. Mount Semeru in East Java has the most eruptions with 350 events.

(Read: Trends in Volcanic Eruptions in Recent Years)